Humidifier



J. A. WILSON Dc., 6, 193s;

HUMIDIFIER Filed Feb. 2l, 1936 Ja A. D15/Jak Patented Dec. 6, 1938PATENT OFFICE HUMIDIFIER John A. Wilson, Detroit,

Mich., assignor to The Timken-Detroit Axle Company, Detroit, Mich.,

a corporation of Ohio Application February 2.1, 1936, Serial No. 65,137

8 Claims.v

This invention relates to humidifying apparatus, and more particularlyto such apparatus as employed in connection with furnaces employing oilburning means or other intermittently operated heating means. Thepresent application constitutes a continuation-in-part of my applicationSerial No. 22,246, filed on May 18, 1935, entitled Liquid fuel burningapparatus. In prior solid fuel burning furnaces and like apparatus ofthe hot air type wherein substantially continuous combustion takesplace, it has been the practice to incorporate a humidifying device,usually in the form of a trough, adjacent one of the heated walls of thefurnace to increase the moisture content of the heated air dischargedfrom the furnace. Such systems have proven generally satisfactory ascombustion in such apparatus is continuous and the Water in thehumidifying apparatus is maintained at a sufliciently high vaporizingtemperature. In oil burning and gas burning hot air furnaces and othertypes of furnaces wherein intermittent operation of the fuel burningmeans is characteristic, I have found that by reason of the entirelydifferent conditions encountered, humidifying devices of the prior artare unsatisfactory.

One of the reasons why prior humidifying apparatus will not operatesuccessfully in a furnace of the intermittently heated type is thatcombustion takes place at spaced intervals and is not continuous withthe result that, during the idle period when the burner or like heatingunit is shut off, the water in the humidifying trough cools to such anextent that when operation is again resumed, considerable time isrequired for the Water to again resume the required vaporizingtemperature with the result that proper humidication of the air beingheated is not obtained.

Humidication problems are rendered even more complex when a fan or likemeans is employed to force the air through the air heating chamber of afurnace at a relatively high velocity because the air by reason of suchforced circulation is not heated to as high a temperature as in anatural draft system. The relatively high velocity of the air increasesthe rate of heat transfer as compared to the rate in old systems withthe result that the temperatures are much lower and therefore water in ahumidifier located therein does not begin to properly vaporize much lessboil.

In overcoming the disadvantages of the prior art, it is a major objectof my invention to provide novel humidifying means that fully meet thepeculiar requirements of oil burning and other intermittently operatingheating apparatus such as gas furnaces and the like.

It is a further object of my invention to provide a novel container foruse in connection with humidifying apparatus employed in a furnacewherein a maximum portion of the surface of the container is subjectedto the products of combustion from the heating means of the furnace attheir highest temperature.

It is still a further object of my invention to provide novelhumidifying means for use in connection with a furnace or like devicewherein the liquid container employed in connection therewith is readilyaccessible for cleaning purposes and for inspection whereby such meansmay be maintained at its highest efliciency at all times.

It is still a further object of my invention to provide a humidifier ofnovel design having a maximum surface area subjected to heat to insure amaximum rate of vaporization with a minimum volume of water so that thehumidifier may be satisfactorily employed in combination with ahumdostat or like automatic control.

A further object of my invention is to provide a novel humidifierparticularly for use in connection with furnaces of the hot air type,wherein on increasing the volume of water contained therein, arelatively greater proportional increase of vaporizing area is obtainedthan in humidiers of prior design, thus insuring increased vaporizationwith an increased volume of water whereby the rate of vaporization maybe easily controlled.

Still a further object of my invention is to provide novel humidifyingapparatus wherein the rate of vaporization is readily controlled byvarying the level of the liquid in the humidifier.

A further object of my invention is to provide novel humidifyingapparatus wherein the evaporating capacity thereof may be easily changedto suit different installations and conditions of operation.

Still a further object of -my invention is to provide a humidifier ofnovel design wherein the area thereof subjected to heat may be readilyreduced or enlarged to correspondingly change the evaporating capacityof the humidifier.

Further objects of this invention will become apparent as thedescription proceeds in connection with the annexed drawing, and fromthe appended claims.

In the drawing- Figure 1 is a vertical sectional view of a hot airfurnace embodying a fuel. burner and a preferred form of humidifier ofthe present invention.

Figure 2 is a fragmental vertical sectional view through the furnace ofFigure 1, illustrating the humidifler'on a larger scale, and the floattank assembly preferably employed therewith.

Figure 3 is a view illustrating the humidifier unit as viewed on line3-3 of Figure 2.

Figure 4 is a view similar to that of Figure 3 illustrating a secondmodification of the humidifier of the present invention.

Figure 5 is a side view of the humidifier shown in Figure 4.

Figure 6 is a sectional plan of a modified form of furnace embodying thehumidifier of Figures 4 and 5.

Figure 7 is a side elevation of a further preferred embodiment of ahumidifier of the present invention wherein the surface thereof may bereadily changed in extent to change the evaporating capacity of thehumidifier.

With continued reference to the drawing wherein like referencecharacters have been employed to designate like parts throughout theseveral views thereof, and with particular reference to Figure 1, afurnace A, in which a preferred embodiment of the humidifying apparatusof the present invention is installed, is illustrated as comprising aninner member ID in the shape of an upright cylindrical shell. Adjacentthe top of shell Ill is an opening with which a short pipe II registers.Encircling the upper part of shell Il), but spaced therefrom is anannular flue pipe I2 which is connected to pipe II. The products ofcombustion, produced by the fuel burning apparatus designated generallyat B, which may be an oil or gas burner of conventional design operableeither intermittently or constantly, pass upwardly along the innersurface of shell I6 and through pipe II into annular ue I2.l As theproducts of combustion pass into annular flue I2 they divide, one halfof the gases going in each direction and passing through the oppositeportions of the annular member to a point where they again join and aredischarged through a pipe I3.

The air to be heated by shell I0 is maintained in contact with thelatter by means of a jacket or second shell I4 which completely enclosesshell I0 and is spaced therefrom to provide an air heating chamber.Preferably the cool air exhausted from the rooms or other space that isbeing heated is conducted through an air inlet pipe I5 secured to jacketI4 adjacent the lower part thereof. As the air is heated and passesupwardly through the jacket I4 around the shell I0, it is conducted intothe rooms by means of conduits such as shown at I5, I'I and I8.

In Figure 1, the paths taken by the air currents have beendiagrammatically indicated by arrows. It will be noted that the cool airentering the jacket I4 by way of member I5 passes upwardly along and iscontacted with the outer surface of the combustion chamber or shell I0.Portions of the upwardly moving air current pass over the inner andouter sides of annular member I2 and are heated thereby. The heated airafter rising in the shell passes into the various rooms through conduitsI6, I'I and I8. In some cases, fans or other means to force circulationare employed in connection with conduit I5.

In order to satisfactorily humidify the air passing through the conduitsI6, I1 and I8, the present invention contemplates the provision of ahumidifying container 25 as shown in Figure 1, container 25 beingpositioned with a portion thereof in contact with the products ofcombustion and a portion thereof in Contact with the air being heated.

With particular reference to Figures 2 and 3, the elongated container 25extends through an opening in the outer wall of annular member I2 and isprovided with a flange 26 which is secured to annular member I 2 in gastight relation. Container 25 is provided with an opening 2l throughwhich the vapors generated in the container may escape and mingle withthe air passing into conduits I6, I'I and I8.

It will be noted from an inspection of Figures 2 and 3 that container 25is relatively small and has comparatively small water capacity. Becauseof its registry with and extension into pipe II, it is located in thedirect path of the products of combustion and therefore the watercontained therein is subjected to maximum heat when the fuel burningmeans B is operating. As shown in Figures l and Z, that section ofcontainer 25 which is exposed to the flow of the products of combustionthrough p ipe II may be of the general shape of a hollow cone and bestreamlined, but preferably it is shaped substantially as the endportion of a prolate spheroid. This arrangement provides a maximum ofheat exchange surface with a minimum of resistance to the flow of theproducts of combustion through pipe I Because of the relatively smallwater capacity of container 25 it is preferred to employ a floatmechanism in connection therewith for maintaining the water at aselected level in the container, a preferred form of the float mechanismbeing shown in Figure 2. The float control as shown in Figure 2comprises a chamber 3B having a support portion 3i, and a pipe 28 tappedinto the bottom wall thereof. Pipe 28 is connected to container 25exteriorly of shell IQ so that none of the hot products of combustioncome into contact with any part of pipe 28. Mounted for rocking movementin container 3B is a lever 3,2 having a collar 33 adjustably mountedthereon. Collar 33 supports a iioat arm 34, the latter being threadedinto collar 33 and functioning as a set screw, so that by rotating thearm 34, collar 33 may be loosened and adjusted upwardly or downwardly onlever 32 so as to adjust the water level within chamber 3Q. A float 35is secured to arm 34 in any suitable manner.

Cooperating with a water inlet is a valve seat which is carried bysuitable linkage 3'! pivotally connected to lever 52. A supply pipe 36is secured to the chamber 30 and communicates with the water inlet. Fromthe structure described it is apparent that the chamber 3Q will befilled with water from pipe 36 to the level shown in Figure 2, when theoat 35 will operate arm 34 and lever 32 to shut off the flow. As waterseeks a constant level, it is apparent that the level of the water inthe container 25 will always be the same as that in chamber 3B. In orderto prevent the water from rising sufficiently high to iiow out of theopening 21 in the container 25 when for some reason or other the floatshould fail to shut off the flow of water, chamber SII is preferablyprovided with an overiiow spout 39 which is located below the level ofopening 2l and connected to a drain.

So long as water pressure is available in pipe 36, chamber 35 andcontainer 25 will have a constant water level maintained therein. It isapparent that the iioat mechanism can be embodied in container 25, butit is preferred to mount the oat in heated parts of the container A andthe adjacent elements of the furnace to thereby insure long life of thefloat mechanism. While the float mecha- ,nismhas not been shown assupported on the furnace, it is preferably mounted on the exterior ofcasing Illiand toward the rear thereof.

From the structure thus far described, it isV apparent that as theburner B is intermittently put in operation, heated air will be suppliedto conduits I5, I1 and I8, and by reason of the comparatively smallvolume of water located in container 25 and because of the location ofthe latter in a highly heated region, the flue gases will rapidly heatthe water to boiling temperature, whereupon the vapor therefrom willrise and mix with the air being heated.

By reason of the construction and location of container 25, it ispossible to readily inspect and `service it. Upon the formation ofadepost or :scale of lime or the like (which precipitates out of thewater at temperatures above 140 F.) in container 25 of sufficientthickness to interfere with the efficiency thereof, a cover on the frontof casing I4 similar to door 45, Figure 6, may be removed and thedeposit easily removed with a suitable scraper.

In Figures 4 and 5 I have illustrated a preferred modification of thehumidifier of Figures 2 and 3. In this modification, the tapered portionof a container 4I is of slightly different shape from that of container25 as shown, a ange 42 being provided to secure the container in gastight relation to annular member I2. An o-pening 43 is providedcorresponding to the opening 21 of container 25, the opening 43 being ofslightly different shape than the opening 21 in that as shown in Figure4, the side walls 44 serve to define a passage 43 extending verticallyabove the center of container 4I to a point adjacent the top thereof.-This arrangement enables the maintenance of a higher water level in thecontainer 4I when greater humidiflcation is desired.

In Figure 6, I have shown a construction corresponding generally to theconstruction shown in Figure 1, with the exception that the outer shellI4' is square or generally rectangular in shape rather than circular asis the shell I4 of the furnace of Figure 1. In such an arrangement, ithas been found preferable to mount the container 4I adjacent a corner ofthe outer shell towards an upper front door 45 of the furnace,communicating with the space between the inner and outer shells Il] andI4. Such an arrangement in a corner not only insures the passage of amaximum quantity of air over the opening of the humidifier but alsoprovides for ready access to the humidifier for inspection and cleaningthereof. The arrangement shown in Figure 6 illustrates a furnace of thetype which is ordinarily supplied with a door provided for the purposeof gaining access to a humidifier pan or the like supported upon thefront wall of the combustion chamber of the furnace. In such furnaces noadditional door need be provided for gaining access to the humidifier ofthe invention as shown in Figure 6.

It is to be noted that the containers 25 and 4I of the present inventionare of such shape that as the water level increases therein, there is amaterial increase of surface area of the container that is directly incontact with the water contained therein. This shape of container whichmay be termed shoe-shaped has been found to be particularly useful inthe heating of water for humidifying purposes whereintermittentlyoperating heating means is employed and has proven muchmore satisfactory in practice than the prior types of containers.

By controlling the level of the water in containers 25 or 4 I, it hasbeen found possible to vary the humidifying action thereof. Since thecontrol of the level of the water in the containers l may readily bevaried by adjustment of the float control device without the furnace, itfollows that the fioat control device affords a ready and convenientcontrol for controlling humidiflcation at all times.

Figure '1 illustrates a further preferred embodiment of the humidifierof the present invention wherein the size of the portion of thecontainer exposed to the heating gases may readily be changed to varythe evaporating capacity of the humidifier. As shown a hollow outercasting or casing llt is provided substantially of the same shape ascasing il of Figure 5, an opening 41 being provided at the top thereofas shown for the escape of vapors generated in the container. Casing 46is formed with a flange 48 to permit of ready fastening to the annularchamber I2 of a furnace, and a liquid inlet 45 is provided correspondingto the inlet 28 of Figure 2.

Flange 48 is formed with a tapped bore of a size to accommodate thethreaded end of a pipe section 49. Section 4S may be a nipple of whichthere are a number of conventional sizes available commercially at verylow price and is preferably closed at its inner end by a standard pipecap 5I.

Since the portions 49 and 5I of the container are subject to the heatedgases passing into and through the annular chamber I2, it is evidentthat by the single stepof changing the size of the nipple of pipesection 49, the surface area of the container in contact with theheating gases may readily be Varied and the evaporating capacity of thehumidier correspondingly varied.

The invention may be embodied in other specinc forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of" theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States LettersPatent is:

l. A humidifier for use in connection with hot air heating systemswherein products of combustion are employed to heat air, a container forliquid to be vaporiaed and discharged into the heated air., saidcontainer being formed in the general shape of a cone, a substantiallyhorizontally extending conduit for conducting products of combustion inheat exchange relation with the air to be heated, said cone beingdisposed with its axis extending substantially horizontally and in sucha manner that the apex thereof is positioned approximately in the centerof said conduit in the path of the products of combustion whereby amaximum rate of vaporizaton of the liquid in said container ismaintained.

2. In a hot air heating system, a source of products of combustionsurrounded by a substantially circular shell, a second shell surroundingsaid rst shell to denne a chamber for the air to be heated, a hollowannulus spaced from said shells and positioned therebetween, a conduitconnecting said annulus with said inner shell to conduct products ofcombustion from said inner shell to said annulus, a container for liquidpositioned in said annulus and extending into said conduit, wherein itis subject to the heat of said products of combustion, said containerhaving an aperture opening into the space between the two shells wherebyvapors from the liquid in the container will be discharged into the airbeing heated.

3. In a hot air heating system, a source f products of combustionsurrounded by a substantially cylindrical shell, a second shell ofgenerally rectangular cross section surrounding said first shell todefine a chamber for air to be heated, a hollow annulus spaced from saidshells and located therebetween, a conduit connecting said annulus withsaid inner shell to conduct the products of combustion from the innershell to said annulus, and a container positioned in said conduit whereit is subject to the heat of the products of combustion, said containerbeing provided with an aperture opening into the Space between saidinner shell and a corner of said outer shell, whereby the vaporsgenerated in said container are discharged into a maximum quantity ofthe air surrounding said annulus.

4. In a hot air heating system, a shell for surrounding a fuel burningmeans and confining the products of combustion therefrom, a second shellsurrounding said first shell and spaced therefrom, an elongatedsubstantially horizontally extending conduit arranged in the spacebetween said shells, means affording fluid communication for the passageof products of combustion between said first shell and said conduit, anda humidifier comprising a substantially horizontally disposed containerextending into the direct path of the product of combustion flowingthrough said fluid communication means and having an opening throughwhich vapors may escape to the space between said shells.

5. A humidifier for use in connection with hot air heating systemscomprising a container for liquid to be vaporized, said container beingformed with a portion of substantially the shape of the end portion of aprolate spheroid having an enlarged lateral opening provided adjacentthe base of said container portion to permit free escape of the vaporsgenerated therein.

6. In a hot air heating system of the character wherein combustion of afluid fuel takes place intermittently, said system embodying means forconfining the products of combustion, a heated air chamber at leastpartly surrounding said confining means, said confining means having anapertured lateral heat exchange wall, a humidifier comprising a hollowfluid container extending substantially horizontally through theaperture in said wall into the path of the products of combustion, thatportion of said container which is disposed in the path of the productsof combustion being of generally conical shape with its base adjacentthe aperture in said wall and its apex within said confining means,means defining a gas tight joint where said container enters saidlateral wall so that the products of combustion are prevented fromescaping to said chamber, and means externally of said confining meansfor introducing liquid into said container, said container having anunobstructed opening formed therein above the liquid level and outsidesaid confining means whereby vapors generated in said container mayescape directly into the warm air in said heated chamber.

'7. In the hot air heating system defined in claim 6, said meansdefining a gas tight joint comprising a lateral fiange on said containerlarger than the aperture in said lateral wall and means for securingsaid fiange to said lateral wall.

8. In combination with a lateral wall of a combustion chamber and ahumidifier adapted to be mounted upon and extend through the lateralwall of said combustion chamber comprising an elongated liquid containerhaving one end of relatively large cross-section and being provided withintegral curved tapering walls converging to form a closed portion ofrelatively small crosssection at the other end of said container, saidcontainer being supported upon said lateral wall with its axis generallyhorizontally disposed, the larger end of said container being adjacentthe chamber wall and extending outside thereof and the smaller inner endof said container being disposed wthin said combustion chamber, and saidcontainer being apertured at its larger end outside said chamber andabove the normal water level in said container to permit free escape ofvapors generated in said container.

JOHN A. WILSON. u

